The windowsill board is a few centimeters
If there is a texture of marble, 2cm thick, if the force, then the width of the probe can not be greater than 5cm, more than 5cm outside the exploration site can not force
Granite strength is much better,
Combined with the actual situation of the actual decision it
Depending on the material, size, and the use of the situation, to determine. If the windowsill board to force the future, such as standing, put flower pots, etc., the size of the outer probe is best than half of the windowsill. If not appropriate may be appropriate, it is best not to be greater than a quarter, more than one-half of the risk of falling.
Generally eaves out 3 to 5 cm, about 10 cm left and right sides, because the other three windows to cover the window sets, window cover line width is 6 to 8 cm look.